ashburton/hakatere river flow and allocation regimes

Ashburton/Hakatere River flow and allocation regimes: Update of modelling results

Prepared for Environment Canterbury

November 2012

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Whilst NIWA has used all reasonable endeavours to ensure that the information contained in this document is accurate, NIWA does not give any express or implied warranty as to the completeness of the information contained herein, or that it will be suitable for any purpose(s) other than those specifically contemplated during the Project or agreed by NIWA and the Client.

Authors/Contributors: Graeme Horrell Roddy Henderson Jani Diettrich

For any information regarding this report please contact:

Graeme Horrell Scientist Applied Hydrology +64-3-343 8036 [email protected] National Institute of Water & Atmospheric Research Ltd 10 Kyle Street Riccarton Christchurch 8011 PO Box 8602, Riccarton Christchurch 8440 New Zealand Phone +64-3-348 8987 Fax +64-3-348 5548

NIWA Client Report No: CHC2012-140 Report date: November 2012 NIWA Project: ENC12504

Ashburton/Hakatere River flow and allocation regimes: Update of modelling results 3

Contents

1 Executive Summary ...................................................................................................... 5

2 Introduction ................................................................................................................... 6

3 Model description development and upgrades .......................................................... 7

3.1 Model description ................................................................................................... 7

3.2 Why a model was developed and what it does ...................................................... 7

3.3 Model upgrade ....................................................................................................... 8

3.4 North Ashburton River at Confluence – leakage model ......................................... 8

3.5 Consent corrections ............................................................................................. 12

3.6 Other model enhancements ................................................................................ 12

3.7 Model updating .................................................................................................... 12

3.8 Model reliability .................................................................................................... 13

3.9 Model outputs ...................................................................................................... 13

4 Modelled scenario ....................................................................................................... 14

4.1 Scenario 1 ............................................................................................................ 14

4.2 Scenario 2 ............................................................................................................ 14

4.3 Scenario 3 ............................................................................................................ 15

5 Results ......................................................................................................................... 16

5.1 Scenario 1 ............................................................................................................ 17

5.2 Scenario 2 ............................................................................................................ 22

5.3 Scenario 3 ............................................................................................................ 27

6 Discussion ................................................................................................................... 31

7 Acknowledgements .................................................................................................... 33

8 References ................................................................................................................... 33

Appendix A Consented abstractions from the Ashburton Catchment ......................... 34

Tables

Table 3-1: North Branch leakage model inputs and outputs (l/s). 9 Table 3-2: Regression equations relating flow (l/s) at water level recorder sites to

tributary flows (l/s). 13

4 Ashburton/Hakatere River flow and allocation regimes: Update of modelling results

Table 4-1: 2004 NRRP A and B Permit minimum fows and locations. 14 Table 4-2: Ashburton District Council stockwater abstractions and proposed

reductions. 15 Table 5-1: Further explanation of figures and tables. 16 Table 6-1: A permit irrigation season reliability (% of time) of supply for Scenario 1, 2

and 3. 31

Figures

Figure 3-1: Pudding Hill river channel downstream of State Highway 72. 10 Figure 3-2: Relationship between North Branch flows measured at the Old Weir and

gains in flow (Pudding Hill) contribution to the Methven Auxiliary on the North Branch. 11

Figure 3-3: Net North Ashburton flow at the Confluence with the South Ashburton, allowing for leakage versus without leakage. 11

Figure 5-1: Scenario 1 A block irrigators reliability of supply. 17 Figure 5-2: Scenario 1 residual flows at minimum flow locations (irrigation season). 18 Figure 5-3: Scenario 1 residual flows at minimum flow locations (non-irrigation season). 19 Figure 5-4: Scenario 1 ADC stockwater reliability of supply (irrigation season). 20 Figure 5-5: Scenario 1 ADC stockwater reliability of supply (non-irrigation season). 20 Figure 5-6: Scenario 1 B block irrigators reliability of supply (irrigation season). 21 Figure 5-7: Scenario 1 B block irrigators reliability of supply (non-irrigation season). 21 Figure 5-8: Scenario 2 A block irrigators reliability of supply. 22 Figure 5-9: Scenario 2 residual flows at minimum flow locations (irrigation season). 23 Figure 5-10: Scenario 2 residual flows at minimum flow locations (non-irrigation

season). 24 Figure 5-11: Scenario 2 ADC stockwater reliability of supply (irrigation season). 24 Figure 5-12: Scenario 2 ADC stockwater reliability of supply (non-irrigation season). 25 Figure 5-13: Scenario 2 B block irrigators reliability of supply (irrigation season). 26 Figure 5-14: Scenario 2 B block irrigators reliability of supply (non-irrigation season). 26 Figure 5-15: Scenario 3 A block irrigators reliability of supply. 27 Figure 5-16: Scenario 3 residual flows at minimum flow locations (irrigation season). 28 Figure 5-17: Scenario 3 residual flows at minimum flow locations (non-irrigation

season). 28 Figure 5-18: Scenario 3 ADC stockwater reliability of supply (irrigation season). 29 Figure 5-19: Scenario 3 ADC stockwater reliability of supply (non-irrigation season). 29 Figure 5-20: Scenario 3 B block irrigators reliability of supply (irrigation season). 30 Figure 5-21: Scenario 3 B block irrigators reliability of supply (none-irrigation season). 30

Reviewed by Approved for release by

George Griffiths Charles Pearson


1 Executive Summary The Ashburton catchment hydrology model of Horrell (2009) has been upgraded and extended to enable modelling of three catchment management scenarios, the third being that of the proposed sub-regional plan.

The modelling results are described in terms of water users’ reliability of supply and residual flows at eight key water management locations in the Ashburton catchment.


2 Introduction The objective of this study is to update and apply the Ashburton flow model developed by Horrell (2009) to demonstrate the impact and effectiveness of the Proposed Sub-Regional Plan for the Ashburton Catchment. In this report we:

Describe the model, say why it was developed, what it does and what information it provides.

Resolve a point of difference on the model noted in a peer review in 2002 by Richard de Joux and John Young+, on the handling of channel leakage from the North Branch. (A meeting with the first reviewer resulted in an agreed methodology for handling leakage.)

Check Environment Canterbury’s consent data base, to find and remove inconsistencies in an earlier dataset provided to NIWA for modelling. Reload revised values into the model together with the specific tributary groundwater stream depletion estimates updated by Environment Canterbury Groundwater Scientist, Matt Smith.

Include recorded flow data from December 2004 to April 2010 for Bowyers and Taylors tributaries.

Update the model dataset from the existing end date of July 2008 to include data up until April 2010.

Apply the model to test three scenarios.

− Describe the results of running three scenarios and the effect on residual flows and reliability of supply for water users; and compare irrigator reliability of supply with current restrictions measured at State Highway One.

+ now deceased


3 Model description development and upgrades

3.1 Model description A surface and groundwater investigation was undertaken between 1995 and 2000 to establish what the Ashburton tributaries and mainstem natural flow regime would be without abstraction. The Ashburton catchment has had water abstracted since the 1870’s and is now highly allocated.

Ideally a long period of daily timeseries (modelling period here is 28 years) of river flow information at all the multiple river locations plus all abstraction and all bywash locations is required to determine the naturalised flow record at a daily time step. This is impossible as abstractions, bywash and flow at key stream locations across the plains are not continuously measured

The investigation involved concurrent flow measurements at 56 locations, including proposed minimum flow locations, abstraction and bywash locations, and included four permanent flow recorders and 7 monitoring wells.

The detailed concurrent flow measurement investigation does however provide adequate information to determine relationships (regressions Table 3-2) to extend and produce flow records at non-permanent flow locations from the permanently measured (primary sites) locations. These are the key components of the model. While a daily timeseries is impossible to attain, this model provides an adequate statistical method with monthly distributions as outputs.

The modelling of the scenarios are based upon the full record of the South Branch at Mt Somers (1967 to 2010), North Ashburton at Old Weir (1982 -2010) and Taylors from (2004 to 2010).

The individual monthly distributions resulting from the scenarios provide residual flow at the key minimum flow locations as well as the essential reliability of supply figures for water users.

The monthly distributions were combined to provide outputs for the irrigation season (October to April inclusive) and winter season (May to September) show in section 5 Results.

3.2 Why a model was developed and what it does A model was developed to simulate and display how the Ashburton River and its tributaries would respond under the provisions of the Natural Resources Regional Plan (NRRP) (ECan 2004). The model integrates six tributaries, their residual flows, their stockwater and irrigation abstractions and their individual minimum flows in order to provide information on reliability of supply for all users. Furthermore, it provides valuable information about when and where abstractions could be reduced. But, most importantly, it predicts the behaviour of the residual flow regime at key tributary and main stem locations.


3.3 Model upgrade The model was updated with additional flow information from 30 July 2008 to 8 April 2010. This extends many tributary records from 8 May 1982 to 8 April 2010, nearly 28 years of data (Section 3.6).

The consented abstraction information for the tributaries and mainstem were corrected and entered into the model (Section 3.5).

The North Branch at Confluence leakage model (section 3.4 below) was added to assess the naturalised flows at this location

Taylors at Confluence flow distributions were upgraded from flow recorders on Bowyers and Taylors, replacing regression values (Section 3.6 (b))

3.4 North Ashburton River at Confluence – leakage model To allow modelling of the consequences of returning irrigation and stock water takes to the North Ashburton River, a model of leakage to the river bed was needed for the North Ashburton at the Confluence (with the South Ashburton River). This is because not all water returned to the river at a given take point will add to the flow at the Confluence. Until now, two extreme positions had been adopted: one, that all returned water would reach the Confluence; the other, that no returned water would reach the Confluence. The truth lies in between, and the model provides the best answer to this question.

A number of flow measurement gauging runs were available between 1998 and 2000. The dataset comprised flows from the recorder on the North Ashburton, gaugings of flow at the confluence with the South Ashburton, and measurements of major takes and bywash with estimates of the minor takes along the reach between these two locations. The data are shown in Table 2-1.

A relationship was required to populate column 5 of Table 3-1, viz the Pudding Hill contribution to North branch flows. Pudding Hill Stream enhances the North Branch mostly as subsurface flow; this is a steep channel which frequently has no observable surface flow (Figure 3-1). The subsurface delay times are the likely reason for the poor relationship with the North Branch at Old Weir measured flows (Figure 3-2). If more concurrent gaugings were available then the scatter and degree of correlation may still not improve. In 2004 when this issue arose the author considered this relationship to be too poor to use.

However, it is now agreed that by using this relationship (Figure 3-2) the North Branch leakage analysis can be advanced. In Figure 3-2 the North Branch flow measured at the Old Weir appears on the horizontal axis while the additional flow derived from a water balance at below the Methven Auxiliary stockwater take provides the Pudding Hill stream contribution on the vertical axis.

The total surface flow coming into the North Branch is the Old Weir + Pudding Hill ((column 5 - note that five of the 12 values are measured increases, while seven are from the regression shown in Figure 3-2) + 10 % of the gauged inflows of O’Sheas and Mt Harding (90% of the flow is assumed to be upstream losses from the North Branch and 10 % assumed to be rainfall contribution – as recharge into these spring fed streams) (Table 3-1).


Table 3-1: North Branch leakage model inputs and outputs (l/s).

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Date Old Weir

(6 am)

Residual no flows Pudding Hill

(tribs u/s of

Methven auxillary

Total surface inflows (sum of cols 2 to

5)

Abstraction Bywash Coniston removed

Net flow at confl.

w/o leakage (col 6 + col 8 – col 7)

Actual measured

minus Coniston

Leakage Estimate (col 9 – col 10)

Leakage model linear

residual vs net

Net flows with

leakage

Net flow with

leakage minus actual

(residua)

O’Shea Mt Harding

24/06/1998 4080 44 131 581 1440 4 284

05/10/1998 6041 39 954 1141 7281 2325 4 4960 2546 2414 2898 2062 -484

20/01/1999 2678 12 184 117 2815 2458 4 361 242 119 231 130 -112

29/01/1990 2631 588 416 86 2817 1973 4 848 170 678 513 335 165

05/02 /1990 2693 31 261 122 2845 2469 4 380 184 196 242 138 -46

11/02/1990 2570 33 371 70 2681 2685 4 1 136 -135 22 0 -136

25/02/1990 2084 506 123 0 2147 1979 4 172 110 62 121 51 -59

09/03/1990 2288 34 398 21 2352 2313 4 43 115 -72 46 0 -115

23/03/1990 2738 58 436 515 3302 2457 4 849 207 642 514 335 128

26/03/1990 4790 255 693 1658 2438 4 1428

21/12/1990 6659 24 775 1258 7997 2810 385 5572 2196 3376 3253 2319 123

29/02/2000 4646 19 733 140 4861 2646 540 2755 573 2182 1619 1136 563

Bias 3

RMS error 257


The leakage model will be used to assess losses along the reach, and is driven by modelled flows at the downstream end of the reach (Table 3-1). Thus the system to be modelled is the reach, its leakage and its inflows and abstractions. Total inflows along this reach of the river are the sum of the upstream river flow (North Branch at Old Weir, column 2), Pudding Hill Stream (column 5) and the rainfall component of O‘Sheas and Mt Harding (columns 3 and 4 respectively). It is assumed that all other flow in these two tributaries has leaked from the North Branch and is thus recycled within the reach. The rain recharge value has been set at 10% of the flow in these two tributaries. Column 6 is the net inflow to the reach. Column 7 is the sum of measured and estimated abstractions. Column 8 is the Coniston bywash. Column 9 is the expected North Ashburton flow at the Confluence with the South Ashburton if there was no leakage to groundwater outside the reach. Column 10 is the measured flow at the Confluence. Column 11 is the difference between columns 9 and 10, and represents the estimated leakage. We examined these residual values with respect to other measured quantities, and found a reasonable relationship with the expected flow at the Confluence (Figure 3- 3).

Figure 3-1: Pudding Hill river channel downstream of State Highway 72.

We excluded the values from the single winter measurement set (24 June 1998) because they plotted as a significant outlier, and were not representative of the usual conditions during the irrigation season. We also excluded the values from 26 March 1999 as the reach was gradually recharging after a significant dry spell.

The linear regression of Figure 3-3 is applied to the estimated flows without leakage from column 11 to give the estimated leakage (column 12). This is subtracted from the estimated flow of column 9 to give the estimated net flow at the confluence, set to be always greater than or equal to zero (column 13). Differences between the modelled flow at the confluence and the measurements are in column 14. At the bottom the bias (3 l/s) and the RMS error (257 l/s) is shown.


Figure 3-2: Relationship between North Branch flows measured at the Old Weir and gains in flow (Pudding Hill) contribution to the Methven Auxiliary on the North Branch.

Figure 3-3: Net North Ashburton flow at the Confluence with the South Ashburton, allowing for leakage versus without leakage.

515

1658

1258

14070

y = 0.3348x ‐ 794.92R² = 0.3869

0

500

1000

1500

2000

2500

3000

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

North Ashburton flow gain to M

ethven Auxillary (l/s)

North Ashburton at Old Weir flow (l/s)

y = 0.5801x + 21.405R² = 0.9523

‐500

0

500

1000

1500

2000

2500

3000

3500

4000

0 1000 2000 3000 4000 5000 6000

Leakage L/s

Net Flow without leakage L/s

Net vs Actual

Linear (Net vs Actual)


The general result of the application of this model is that approximately 60% of flows in the river are lost to groundwater. It is not reasonable to assume that this proportion persists at high flows in the river, and so application of this relationship is capped at 5,000 l/s (a maximum loss rate of 5,000 l/s). This model is applied to a daily flow series of the natural flows in the North Ashburton and its major surface flow tributaries, to derive a natural flow series at the Confluence

This groundwater-surface water interaction relationship could be described with a curve rather than a straight line. We looked at using a curve, but it would show losses peak at about 3,000 l/s whereas it is believed to be more. The straight line was employed to give a peak at 5,000 l/s. Also the straight line goes through zero as required, which the curve did not.

Richard de Joux commented on the above analysis:

“I have looked at your data and assumptions and agree with your methodology. Even though the “crude bit” might seem to be crude, in reality I would not expect a very good relationship because there is considerable storage within the gravel fan of Pudding Hill and there will be variable time delays when this water is released from storage back into the North Ashburton River. Your method does allay my concern regarding how abstractions should be treated within losing reaches of the river.”

3.5 Consent corrections Time was spent at Environment Canterbury (ECan) offices and with, the assistance of Sarah Hunt (ECan), many inconsistencies, and consents located in the incorrect tributaries, were identified. As a result, A block irrigators were reduced on the North Branch by 33 % and on Mt Harding Stream by 91%. These were the two tributaries of concern to the author.

The derived consented abstractions for the tributaries applied to the updated model are listed in Appendix A.

3.6 Other model enhancements (a) The flow records were split into two seasons; irrigation (1 October to 30 April) and

non-irrigation or winter season (1 May to 30 September). Each season was modelled to provide information on the likely residual flows at the minimum flow locations. In addition, the records were split into monthly periods for each year of analysis. Distributions were completed for individual months as well as for the combined months of the irrigation and non-irrigation seasons.

(b) In December 2004 ECan installed water level recorders on Bowyers Stream and Taylors Stream; records (2004 to 2010) from these sites were preferred to the previously predicted ones using flows from the North Branch and nearby Hillview groundwater levels.

3.7 Model updating The model was extended with data from 30 July 2008 to 8 April 2010. The method used was the same as that described in the Horrell (2001, 2004) reports for six of the eight regressions. The equations from Horrell (2004) are shown in Table 3-2 along with the updated Taylors regression using the two new recorders Bowyers at State Highway 72 and Taylors at State


Highway 72 from Horrell (2009). The revised North Branch at South Branch regression equation (Table 3-2) is also included.

A flow record was produced for all key locations. The primary site records have many gaps (approximately 1 year in 26 years). Gaps were omitted from the analysis.

Table 3-2: Regression equations relating flow (l/s) at water level recorder sites to tributary flows (l/s).

Regression equations (flow, l/s) Adjusted

r2

Standard Error l s-1

Number of

values

South Ashburton at Valetta = (Mt Somers x 0.892) – 141 .94 413 12

Taylors at South Branch confluence = (Bowyers + Taylors) x 1.577 – 1,018 .92 412 19

South Branch at Nth Confl = (Valetta + Taylors) x 1.242 + 2,306 .98 509 10

Leakage = (Old Weir + Pudding Hill + 10% O’Shea +10% Mt Harding) x 0.5801 +21.4 (Note: Leakage is maximised at 5,000 l/s)

North Branch at Sth Conf = (Old Weir + Pudding Hill + 10% O’Shea +10% Mt Harding) - Leakage

.95 234 10

SH1 = ( Sth Branch at Confl + Nth Branch at Confl) x 1.049 + 75 .99 460 13

Digby’s Bridge = Nth Branch at Confluence x 0.982 - 443 .99 152 9

Mt Harding = (log10 Old Weir) x 1,530 – 4,352 .78 134 11

O’Shea + Snowden = (log10 Old Weir) x 513 + (Ashburton Forks x 0.638 ) + 4

.83 79 10

3.8 Model reliability The model was constructed using the regressions displayed in Table 3-2. Their standard errors should be taken into account when evaluating model outputs.

3.9 Model outputs The model was used to establish a natural flow time series which is able to be used to test various scenarios.


4 Modelled scenario Ideally modelling the flow regime status quo along with management scenarios in a daily time step model is preferable. However such modelling is impossible because catchment wide abstractions were not measured. Without any knowledge of where or when abstractions occurred, it is impossible to model what was taken and to calculate its reliability. To attempt to overcome this, a dataset of naturalised flows was used from which prescribed allocations can be modelled. Model outputs such as residual flows at minimum flow locations or abstraction reliability were estimated.

The residual flow data recorded at SH1 (the current minimum flow site) from 1996 to the present is useful only to provide fully restricted information (all abstractions cease) for comparison with the scenario outputs.

The management options to be examined and their modelling requirements are described in the following sections.

4.1 Scenario 1 This represents the worst case abstraction scenario representing the status quo with full instantaneous consented takes for the Rangitata Diversion Race Limited (RDRL) from the South Ashburton, Ashburton District Council (ADC) stockwater abstractions as they stood at the beginning of this LWRP process, and all A and B permit maximum rates of abstraction within the catchment. Modelling of minimum flows on all tributaries are as proposed in the 2004 NRRP displayed in Table 4-1.

Table 4-1: 2004 NRRP A and B Permit minimum fows and locations.

Tributary A and B permit minimum flow location

A Permit minimum flow (l/s)

B Permit minimum flow (l/s)

South Branch Below RDR intake 3,200 4,000

Taylors At South Branch confluence 500 3,700

North Branch At South Branch confluence 1000 4,000

O’Sheas Above North Branch confluence 450 1,000

Mt Harding Aitken Road 500 1,100

Pudding Hill Above ADC intake 80 1,600

Main stem State Highway 1 6,000 Oct – April 5,000 May - Sept

14,000

One change is to the mainstem at State Highway One (SH1) minimum flow with the introduction of the Land and Water Regional Plan 6,000 l/s all year, a modification of the 2004 NRRP, 6,000 l/s from October to April (inclusive) and 5,000 l/s from May to September.

Those groundwater abstractions not subject to a minimum flow (such as ADC) will not be restricted when a minimum flow in the tributary or mainstem occurs.

4.2 Scenario 2 This is the same as Scenario 1 with one change - the A permit surface water abstractions are modelled at their average rate of abstraction instead of their maximum instantaneous rate.


This scenario represents A permit (maximum) abstraction rates closer to what would really occur.

4.3 Scenario 3 This represents the notified LWRP and has the following modifications:

RDR, A permit is reduced to 5,100 l/s from 7,100 l/s and is subject to a residual flow of 3,200 l/s in summer and 2,300 l/s in winter, and B Permit provides RDR with a take of 2,000 l/s.

ADC consented takes from the Ashburton Catchment are reduced by a total of 2,000 l/s. As the most difficult river reach to achieve the LWRP minimum flows is the North Branch, the largest reduction to ADC takes is on the mainstem and tributaries of the North Branch. The method employed to achieve this was to reduce the ADC surface takes on the North Branch mainstem and tributary takes by 57 %. The South Branch and Taylors takes are reduced by 30% (Table 4-2).

Table 4-2: Ashburton District Council stockwater abstractions and proposed reductions.

Tributary Name of abstraction Total abstraction

l/s

Reduction l/s

Reduction %

Remainingtake l/s

Taylors Bushside Goughs Carneys

376 113 30% 263

Pudding Hill Pudding hill 509 290 57% 219

Mt Harding Winchmore 566 323 57% 243

North Branch Main Stem Methven Auxillary 1,133 646 57% 487

North Branch Main Stem GW Melrose and unnamed Stream depletion 25

0 0% 25

Nth Branch Main Stem McFarlanes Tce 84 48 57% 36

South Branch above RDR Brothers 1,699 510 30% 1189

South Branch above RDR Woolshed 113 34 30% 79

South Branch below RDR Langdons120 and 42 (42 part of 120)

120 36 30% 84

All other A permits were modelled at their average rate of take. Groundwater stream depletion takes of 5 l/s or more were subjected to a minimum flow while those under 5 l/s were able to continue exercising their abstraction after a minimum flow was reached.

B permits abstract at their full rate of take.

Greenstreet Irrigation Scheme abstracts only from South Branch (not also from O’Sheas as is the case currently) and with LWRP notified minimum flow.


5 Results The results of modelling Scenario’s 1, 2 and 3 are described below. Further definitions are available in Table 5-1.

Table 5-1: Further explanation of figures and tables.

Example Explanation

Residual River flows

% of time below minimum flow Minimum flow is the level at which irrigators are on full restriction. This is the % of time irrigators are on full restriction.

% of time at minimum Flat lining at minimum flow indicates the duration of time the residual flow is low due to stockwater and irrigation abstractions. Irrigators may reduce abstractions to maintain flows just above the minimum flow.

Irrigation and stockwater reliability

Full abstraction All abstractions start at full abstraction on the left of the graph, the reliability of supply of the full abstraction is derived from the horizontal axis as a percentage of time.

Full restriction (no abstraction) River is below the minimum flow (or for stockwater, natural river flows have depleted) there is no irrigating and the abstraction line drops to zero. The period of time at full restriction can be derived from the horizontal axis as a percentage of time.

Partial restriction The period an irrigator cannot take their full abstraction to avoid reducing the flow below the minimum

The current reliability relates to actual use of water and is obtained from the residual flow measured at the SH1 recorder in terms of irrigation occurring or not occurring, whereas, the rest of the scenario analyses provide values for irrigation abstractions for the potential irrigable water available.

The full abstraction of the 7,100 l/s RDR take from the South branch is a large abstraction which equates to approximately 70% of the natural South Ashburton River mean flow at the RDR intake. It is not exercised very often as water from the Rangitata River frequently satisfies RDR’s needs. The flows and management decisions of the RDR related to the Rangitata River abstraction are not modelled here, so a full take by the RDR is assumed. However an observation of RDR’s abstraction record from the South Branch for the period 21 September to 2009 to 5 September 2011 while only for two years, shows the full 7100 l/s was never abstracted, the maximum take was 6690 l/s for a short period and more than 5000 l/s was abstracted for only 2% of .this time.

The values in the results which follow simply display the water available from the South Branch, and the low reliability of supply for the full abstraction displayed in the graphs is a reflection of the very large consented take.

The modelling of the scenarios are based upon the full record of the South Branch at Mt Somers (1967 to 2010), North Ashburton at Old Weir (1982 -2010) and Taylors from (2004 to 2010). The primary sites were applied to the respective locations and tributaries using the regression equations in Table 3-2, with the resulting flow distributions being the information the model uses.


5.1 Scenario 1

5.1.1 A Block reliability of supply

As described above it is difficult to describe the impacts upon the large RDR take knowing the full use of this abstraction occurs only rarely.

For A Block irrigators reliability of supply refer to Figure 5-1.

Figure 5-1: Scenario 1 A block irrigators reliability of supply.

Taylors irrigators would be able to take the full abstraction for 25 % of the time and abstract less than their maximum rate for 75 % of the time. This is similar to the RDR South Branch situation which is, a very large take compared to the flow regime.

O’Sheas abstraction graph shows that the one large Greenstreet take along with other O’Sheas irrigators would not be fulfilled for 99% of time. However the supplementary take from the South Branch would partially improve the reliability of supply in this scenario for Greenstreet who would be the best off for reliability of all irrigators in Scenario 1, although they would be below what could be actually achieved today.

Mt Harding and North Branch irrigators would receive their full allocation for approximately 72 % and 80 % of the time respectively but their abstractions would be reduced for the remaining 28 % and 20 % of the time.

5.1.2 Residual flows at minimum flow locations

The South Branch below the RDR will be flat lined (Figure 5-2) for approximately 68 % of the time, while Taylors stream will be flat lined at the minimum flow for at least 57 % of the time. O’Sheas will be flat lined for 95 % at the minimum flow.


The Pudding Hill ADC stockwater take is very large for the size of the stream and the river will be below the minimum flow for 16 % of the time.

The North Branch and Ashburton mainstems will not experience long periods of flat lining ( both 9%), but they will both be below the minimum flow for 11 % of time.

For winter residual flows – the South Branch below RDR would be flat lined for 67 % of the time and on full restriction for 8 % of the time. SH1 would be below the minimum for 4 % of the time (Figure 5-3).

Figure 5-2: Scenario 1 residual flows at minimum flow locations (irrigation season).


Figure 5-3: Scenario 1 residual flows at minimum flow locations (non-irrigation season).

5.1.3 ADC stockwater reliability of supply

The only reduction to stockwater abstractions (Figure 5-4) is the take from Pudding Hill where during the summer the take will be reduced for 28 % of the time while in winter for 9 % of time (Figure 5-5).


Figure 5-4: Scenario 1 ADC stockwater reliability of supply (irrigation season).

Figure 5-5: Scenario 1 ADC stockwater reliability of supply (non-irrigation season).


5.1.4 B Block reliability of supply

Taylors and North Branch B block abstractors would have the opportunity of full abstractions during the irrigation season (Figure 5-6) for 12 % and 25 % of the time.

During the winter (non-irrigation season) the full abstraction from Taylors is available 39 % and for North Branch 34 % of the time (Figure 5-7)

Figure 5-6: Scenario 1 B block irrigators reliability of supply (irrigation season).

Figure 5-7: Scenario 1 B block irrigators reliability of supply (non-irrigation season).


5.2 Scenario 2


Here too as described above it is difficult to describe the impacts upon the large RDR take knowing the full use of this abstraction occurs only rarely.


Figure 5-8: Scenario 2 A block irrigators reliability of supply.

Taylors irrigators would be able to take the full abstraction for 73 % of the time and abstract less than their maximum rate for 27 % of the time. This Scenario considerably reduces the consented takes from 4,020 l/s down to 365 l/s owing to the averaging of consented abstractions.

O’Sheas abstraction graph shows the one large Greenstreet take along with other O’Sheas irrigators would not be fulfilled for 97 % of time, but the supplementary take from the South Branch would partially improve the reliability of supply in this scenario for Greenstreet.

Mt Harding and North Branch irrigators would receive their full allocation for approximately 76 % and 87 % of the time respectively but their abstractions would be reduced for the remaining 24 % and 13 % of the time.


The South Branch below the RDR will be flat lined (Figure 5-9) for approximately 68 % of the time while Taylors stream will be flat lined at the minimum flow for at least 10 % of the time. O’Sheas will be flat lined for 95% of the time.




The North Branch and Ashburton mainstems will not experience long periods of flat lining, but they will be below the minimum flow for 11 % of time.

For winter residual flows the South Branch below RDR would be flat lined for 67 % of the time and on full restriction for 8 % of the time. SH1 would be below the minimum for 4 % of the time (Figure 5-10).




The only reduction to stockwater abstractions (Figure 5-11) is the take from Pudding Hill where during the summer the take will be reduced for 28 % of the time while in winter for 9% of time (Figure 5-12). These are the same results as Scenario 1.



Figure 5-12: Scenario 2 ADC stockwater reliability of supply (non-irrigation season).

5.2.4 B Block reliability of supply

Taylors and North Branch B block abstractors would have the opportunity of full abstractions during the irrigation season (Figure 5-13) for 26 and 27 % of the time respectively.

During the winter (non-irrigation season) the full abstraction from Taylors is available 39 % of the time for North Branch 34% of the time (Figure 5-14).


Figure 5-13:Scenario 2 B block irrigators reliability of supply (irrigation season).

Figure 5-14:Scenario 2 B block irrigators reliability of supply (non-irrigation season).


5.3 Scenario 3


Again as described above it is difficult to describe the impacts upon the large RDR take knowing the full use of this abstraction occurs only rarely.


Figure 5-15:Scenario 3 A block irrigators reliability of supply.

Taylors irrigators would be able to take the full abstraction for 73 % of the time and abstract less than their maximum rate for 27 % of the time.

O’Sheas abstractions show a very high reliability of supply 97 % of the time as a result of the Greenstreet full take being transferred to the South Branch.

Mt Harding and North Branch irrigators would receive their full allocation for approximately 97 % and 98 % of the time respectively which is an improved reliability of supply compared to previous scenarios


The South Branch below the RDR will be flat lined (Figure 5-16) for approximately 55 % of the time at the A permit minimum flow while a further 12 % is due to the B permit abstractions, while Taylors stream will be flat lined at the A permit minimum flow for at least 12 % of the time and for a short duration owing to the B permit takes. O’Sheas will only be flat lined for 1 % of the time.




The North Branch and Ashburton mainstem will not experience long periods of flat lining but they will be below the minimum flow for 1 % and 2 % of time respectively.

For winter residual flows the South Branch below RDR would be flat lined for 28 % of the time and on full restriction for 1 % of the time. SH1 would be below the minimum for 3% of the time (Figure 5-17).




ADC would have 100% reliability of supply from all of their abstraction locations. (Figure 5-18 and Figure 5-19).


Figure 5-19:Scenario 3 ADC stockwater reliability of supply (non-irrigation season).


5.3.4 Block reliability of supply

South Branch, Taylors and North Branch B block abstractors would have the opportunity of full abstractions during the irrigation season (Figure 5-20) for 23, 26 and 37% of the time respectively.

During the winter (non-irrigation season) the full abstraction from South Branch is available for 23 % of the time, Taylors is available 39 % of the time and North Branch for 47% of the time (Figure 5-21).

Figure 5-20: Scenario 3 B block irrigators reliability of supply (irrigation season).

Figure 5-21: Scenario 3 B block irrigators reliability of supply (none-irrigation season).


6 Discussion In summary, B permits have adequate reliability of supply during summer and winter to fill storages in all Scenarios.

ADC stockwater has 100 % reliability of supply in Scenario 3 and is not subjected to restrictions at minimum flow.

Considerable flat lining has the potential to occur in all scenarios on the South Branch downstream of the RDR intake as well as Taylors at the South Branch confluence. However these residual flows will be higher than those that occur under the current management regime.

The scenarios are summarised from an irrigator’s perspective in Table 6-1. Overall the scenario with the greatest time with full abstractions and least time in partial abstraction and full restriction is Scenario 3. In Scenario 3 there is extremely high reliability of supply results for irrigators on O’Sheas, Mt Harding and the North Branch. As discussed earlier the RDR take on the South Branch is a very large abstraction for the size of the river and one cannot expect high reliability of supply. Taylors is in a similar situation to the South Branch and in some occasions goes dry (mainly due to the stockwater abstractions upstream). Thus Taylors has the largest result for the percentage of time in full restriction of all the tributaries. This has been clear to the local irrigators for many years and they have actively secured B permit water for storage to enhance their reliability of supply during the irrigation season.

Table 6-1: A permit irrigation season reliability (% of time) of supply for Scenario 1, 2 and 3.

% of time South Branch

below RDR

Taylors O’Sheas Mt Harding

North Branch at South

confluence

SH1 Actual SH1

Scenario 1: A permits irrigation season

Full abstraction 24 25 1 72 80 24 ?

Partial abstraction 69 58 97 7 9 71 ?

Full restriction 7 17 2 21 11 5 12









Irrigators on the South Branch below the RDR down to SH1 (SH1 column) look worse off in Scenario 3 compared with Scenario 2. This occurs because under Scenario 2 the large Greenstreet abstraction is supplied first from O’Sheas and secondly from the South Branch. As a result most of the water for most of the time comes from O’Sheas, and the South Branch supplies the vital top up, but overall has less water abstracted.


In Scenario 3 the full Greenstreet abstraction is only taken from the South Branch. The 2 % of time in restriction is an improvement on the actual situation now which is on average 12 % of the time fully restricted. Another statistic to show is that 75 % of the abstraction from the South Branch would be available 85 % of the time, as displayed in Figure 5-15. The South Branch reliability is also affected by the large RDR take upstream and when modelling RDR’s abstraction every litre that could be abstracted was taken.


7 Acknowledgements The author would like to thank Environment Canterbury staff for assistance in formulating the consent water use list of abstractions for the Ashburton catchment; Sarah Hunt for assistance in formulating the surface water consents and Matt Smith for formulating the stream depletion values for the groundwater consents.

8 References Environment Canterbury. (2004). Variation 1 of the Proposed Natural Resources

Regional Plan, Chapter 5: Water quantity. Canterbury Regional Council Report No. R04/15/5, 285p.

Horrell, G.A. (2001). Ashburton River Low Flow Regime. Canterbury Regional Council Report No. U01/26, Canterbury Regional Council, Christchurch, New Zealand. 71 p.

Horrell, G.A. (2004). Ashburton River Low Flow Regime – review and update Canterbury Regional Council Report No. U04/20, Canterbury Regional Council, Christchurch, New Zealand. 83 p.

Horrell, G.A. (2009). Ashburton River/Hakatere flow and allocation regimes: review and update of options. NIWA Client report CHC 2009-009. 24 p.


Appendix A Consented abstractions from the Ashburton Catchment

Rate/day or

RecordNo ClientName MaxRate Hours/day Stream depletion Concurrent Minimum Flow Condition

CRC000205.1 Mr & Ms H A & M E Smith & Roysmith 38.0 7.7 no min flow (irrigate 100ha)

CRC020501.1 Valetta Farms Limited 18.0 5.7 no min flow (irrigate crops and pasture)

CRC021736.5 Jetol Farm Limited 38.0 4.7 no min flow (irrigate pasture - dairy)

CRC021736.5 Jetol Farm Limited 38.0 9.7 no min flow (irrigate pasture - dairy)

CRC030336.1 Valetta Holdings Limited 24.0 9.2 no min flow (irrigate crops and pasture)

CRC051164 Mr & Mrs G W B & T M Gallagher 105.0 0.3 no min flow (irrigate crops and pasture)

CRC951101 Mr K A Omelvena 6.3 0.1 no min flow (irrigate 1.6ha crops and pasture)

CRC990240.1 Valetta Farms Limited 82.7 1.6 no min flow (irrigate 200ha)

CRC990240.1 Valetta Farms Limited 82.7 2.3 no min flow (irrigate 200ha)

CRC030336.1 Valetta Holdings LTD 24.0 9.2 no min flow

CRC020501.1 Valetta Farms Limited 18.0 5.7 no min flow

CRC000205.1 Mr H A Mrs M E Smith and Roy Smith 38.0 7.7 no min flow

CRC022026 Ashburton District Council 4.9 3.7 no min flow

CRC011245 Rangitata Diversion Race Management Limited 7100 24 7100.00

4 min flows @SH1 80%, 50%, 25% and 0% takes (irrigation, stockwater, generate electricity at highbank power station)

CRC030367 Webbs Transport Limited 30 3.44 4.302min flows @SH1, 1 to stop take and 1 to halve the take. (gravel and sand washing) Not a consumptive use

RDR (for Scenario 3 2000 l/s removed from A Block and added to B Block) 0 0.00 2000 for Scenario 3

CRC951604.1 MrN K & Mrs K L Hammond 80 22 73.332min flows @SH1, 1 to stop take and 1 to halve the take. (Irrigate 80ha)

CRC952164.2 Mr & Mrs Ryan 45.5 9.8 18.582min flows @SH1, 1 to stop take and 1 to halve the take.(take from sth branch to irrigate 180ha)

SCY710033 Ashburton District Council (Brothers) 1699 24 1699.00No min is required (divert & take from sth branch community stock and domestic water supply)

SCY710044 Ashburton District Council (Stoney Creek) 113 24 113.00min flow may be required (to divert and take from stoney creek for community stock and water supply)

Total groundwater abstractions 517.6 67.58

Stockwater 1812.00 1812.00

A Block direct surface takes (excluding stockwater) 7225.50 7191.91

Total 9555.10 9071.49 A Block 9555.10 9071.49

B block 0.00 0.00

A Block surface and groundwater takes with NO minimum flow (excluding stockwater) 517.60 67.58

A Block surface and groundwater takes with minimum flow 7225.50 7191.91

Surface water takes in South Branch (Upper)


Rate/day orRecordNo ClientName MaxRate Hours/day Stream depletion Concurrent Minimum Flow Condition

CRC052609 Alford Park Limited 80.0 16.3 no min flow (irrigate crops and pasture)

CRC991516.1 Mr C J & Mrs A M Allen 65.0 25.0 no min flow (irrigate 300ha)CRC021619 Meadow Lee Limited 135.0 5.0 no min flow (irrigation crops and pasture)

CRC054032 Mr & Mrs D & J G Symons 29.0 0.4 no min flow (dairy shed washdown, milk cooling plant)CRC030598.2 Mr R D L & Mrs D J Withers and AW Trustee Services LTD 53.0 16.6 no min flowCRC980990 Mr & Mrs I L & K A Totty 12.0 6.9 no min flow (irrigation pasture - dairy)

CRC073341.1 Tayler Smith Holdings Limited 200.00 24.00 200.00

2 min flow sites. 1 @SH1 14000L, 1 @ Taylors stream confluence 3000L. To take, dam and use for irrigation of pasture and crops)

CRC074198.1 Mr & Mrs C W M & D Shannon 100 24 100.00

2 min flows @SH1 14000L, & @Taylors Stream confluence 3000L. (Take water from bowyers stream and dam and irrigate)

CRC030560.1 The Picnic Creek Stock Water Scheme Promotion Committee 7.70 5.40 1.73 no min flow (stock water and dairy shed)

CRC951862.4 Jetol Farm Limited 12 23.1 11.55

2min flows @SH1, 1 to stop take and 1 to halve the take ( take from spring fed pond in bowyers stream to supplement water supply for irrigation).

CRC950885 Mr C J & Mrs A M Allen 1000.00 1.60 66.672min flows @SH1, 1 to stop take and 1 to halve the take (take from taylors stream for irrigation).

CRC950885 Mr C J & Mrs A M Allen 500.00 2.10 43.752min flows @SH1, 1 to stop take and 1 to halve the take (take from taylors stream for irrigation).

CRC950930.2 Alford Park Limited 1000.00 5.20 216.672min flows @ SH1, 1 to stop take and 1 to halve the take.( take from taylors stream for irrigation)

CRC950931.1 Mr C J & Mrs A M Allen 500.00 0.30 6.252min flows @SH1, 1 to stop take and 1 to halve the take (Take from Taylors stream for Irrigation).

CRC972504.1 Mr C J & Mrs A M Allen 1000.00 0.40 16.672min flows @SH1, 1 to stop take and 1 to halve the take. (To take for Taylors stream for irrigation)

SCY710045 Ashburton District Council (Taylors at Bushside) do above 141 24 141.00 no min flow (to divert and take from taylors stream for community stock and domestic water supply)

CRC012031 Ashburton District Council (Durrans) 42.00 42.00no min flow (take from taylors stream for community stock and domestic water supply)

CRC012031 Ashburton District Council (Carneys) 10.00 10.00 no min flow

CRC012031 Ashburton District Council (Alford Forest) 42.00 42.00no min flow (take from taylors stream for community stock and domestic water supply)

CRC012031 Ashburton District Council (Gough's Crossing) 141.00 141.00no min flow may be required (take from taylors stream for community stock and domestic water supply)

Total groundwater abstractions 374.00 70.2Stockwater 376.00 376.00A Block direct surface takes (excluding stockwater) 4019.70 363.28

Total 5069.70 1109.50

A Block 4769.70 809.50

B block 300.00 300.00

A Block surface and groundwater takes with NO minimum flow (excluding stockwater) 374.00 71.93 A Block surface and groundwater takes with minimum flow 4019.6 361.56

Surface water takes in Taylor's Stream



CRC082117.1 Tauhei Farms Limited 40.0 8.6 min flow at O'sheas creek 50L (irrigation)

CRC082117.1 Tauhei Farms Limited 30.0 3.9 min flow at O'sheas creek 50L (irrigation)CRC082117.1 Tauhei Farms Limited 40.0 8.6 min flow at O'sheas creek 50L (irrigation) CRC082117.1 Tauhei Farms Limited 96.0 0.7 min flow at O'sheas creek 50L (irrigation)

CRC950584 Mr & Mrs R J T & M A Snowden 38.0 16.3 C - Expired min flow @SH1 (irrigate 89ha) Concurrent CRC921480

CRC951553 Mr D G Aschen 53.0 6.8 No min flow (irrigate 109ha)

CRC951553 Mr D G Aschen 53.0 5.3 No min flow (irrigate 109ha)CRC951596.1 Wallaura Farm Limited 32.0 9.8 No min flow (irrigate 37ha)CRC021199 Mr C J & Mrs A M Allen 26.0 5.9 no min flow

CRC980368.1 Mr M F M & Mrs A B B Talbot and Whitehouse Ten Trustees Limited 42.0 9.0No min flow (supplement flow of water races for irrigation)

CRC921547F.2 Greenstreet Irrigation Society Limited (from Osheas and Snowden) 1200.00 18 896.42 min flows, SH1 and Osheas Creek. This is supplemented by CRC921547C from the South Branch

Total groundwater abstractions 450.00 74.8Stockwater 0.00 0.00A Block direct surface takes (excluding stockwater) 1200.00 896.40

Total 1650.00 971.20

A Block 1650.00 971.20

B block 0.00 0.00

A Block surface and groundwater takes with NO minimum flow (excluding stockwater) 206.00 36.80A Block surface and groundwater takes with minimum flow 1444 934.4

Surface water takes in O'Shea Creek



CRC970931.1 Taralea Farms Limited 45.5 20.3 no min flow (dairy shed water and irrigation 110ha)CRC960067.2 Mr B G & Mrs A S Leslie 21.0 11.2 no min flow (salmon farming) NOT CONSUMPTIVE

CRC021998.1 Mr D A & Mrs A K Shearer 30.00 7.28 9.12 min flows @SH1, 1 to stop take and 1 to halve the take.(irrigation)

CRC951232 Willowdale Farm Limited 28.00 14.50 16.92min flows @ SH1, 1 to stop take and 1 to halve the take.

CRC951530 Mr D A & Mrs A K Shearer 30.00 7.28 9.12min flows @ SH1, 1 to stop take and 1 to halve the take. (Spray irrigation)

CRC960065.2 Mr B G & Mrs A S Leslie 360.00 24.00 360.0 no min flow (salmon farming) NOT CONSUMPTIVE

CRC990718.1 Ashburton Lyndhurst Irrigation Society Limited 114.00 24.00 114.0

Take when discharging from Ashburton-lyndhurst irrigation. (Irrigation 267ha) NOT CONSUMPTIVE OF MT HARDING

SCY710054 Ashburton District Council 566.00 24.00 566.0no min flow (community stock and domestic water supply)


Stockwater 566.00 566.00


Total 699.50 621.40

A Block 699.50 621.40

B block 0.00 0.00A Block surface and groundwater takes with NO minimum flow (excluding stockwater) 45.5 20.3A Block surface and groundwater takes with minimum flow 88 35.1

Surface water takes in Mt Harding


Rate/day or

RecordNo Client Name MaxRate Hours/day Stream depletion Concurrent Minimum Flow Condition

CRC010365 Willowdale Farm Limited 38.0 21.8 No min flow (irrigation)

CRC012324.1 Mr S J & Mrs T M Weily & Leech & Partners Trustees Limited 11.5 3.3 No min flow (irrigation)

CRC020211 J and J Van Polanen Family Trust 45.0 32.5 No min flow (irrigation crops and pasture)

CRC020811 Mr P A Lowe 40.0 21.7 No min flow (irrigation crops and pasture)

CRC021057.1 Pekanga O Te Awa Farms Limited 40.0 44.6 No min flow (irrigation pasture - dairy) 35 x 2 chk later

CRC021199 Mr C J & Mrs A M Allen 26.0 5.9 C No min flow (irrigation pasture and crops)

CRC021613 Mr M J Gaylor 20.0 4.3 C No min flow (irrigation pasture)

CRC021680 Pencarrow Farm Ltd 48.0 7.5 No min flow (irrigation pasture) Moderate

CRC030337 Red Cow Farms Limited 72.0 39.6 C No min flow (irrigation)

CRC030557 Mr & Mrs D D & M E Stewart 39.0 5.8 C No min flow (irrigation crops and pasture)

CRC030721 Mr B K & Mrs P R McIlroy Too deep Too deep

CRC050465.1 Monty Fields Limited 80.0 15.1No min flow (irrigation crops and pasture, dairy shed used, stock water supply)

CRC051210.1 Pekanga O Te Awa Farms Limited 105.0 20.0 C No min flow (irrigation pasture)

CRC090967 Mr J B & Mrs L K Tavendale 41.4 1.0 No min flow (irrigation crops and pasture)

CRC921550B Greenstreet Irrigation Society Limited 30.0 7.9 No min flow (irrigation 44ha)

CRC921550C Greenstreet Irrigation Society Limited 95.0 7.2 No min flow (irrigation 89ha)

CRC921550D Greenstreet Irrigation Society Limited 27.0 8.1 No min flow (irrigation 63ha)

CRC921550E Greenstreet Irrigation Society Limited 28.0 9.6 No min flow (irrigation 28ha)

CRC921550G Greenstreet Irrigation Society Limited 36.0 6.4 No min flow (irrigation 39.7ha)

CRC991516.1 Mr C J & Mrs A M Allen 65.0 25.0 C No min flow (irrigation 300ha)

CRC012671 Mr B K & Mrs P R McIlroy 13.0 7.1 no min flow

CRC940155.1 Mr K L Mrs L Hydes 4.5 0.4 no min flow

CRC921550F Greenstreet Irrigation Society Limited 5.0 1.1 min flow at SH1 bridge

CRC001975.1 Lumphanam Farms LTD 11.4 2.8 no min flow

CRC021499.3 Briggs Holding LTD 11.0 5.1 no min flow

CRC992268 Mr G V R Read 7.0 1.8 No min flow (irrigation 12ha)

Surface water takes in North Branch


CRC000072.1 Mr & Mrs D & J G Symons 60.00 24.00 60.00

3 min flows, 2 @ old weir nrth Branch (pro rata), flow of 10L/s in unnamed drain (irrigation of crops and pasture 140ha) (Band 1)

CRC031720 Methven Golf Club Inc 6.10 5.00 1.272min flows @SH1, 1 to stop take and 1 to halve the take. (irrigation of golf course)

CRC073581.4 Lochan Mor Limited Partnership 200.00 24.00 200.00@ nth branch confluence 3400L. (Storage water in Dam crc082376.3)

CRC103031 Cairndhu Dairy Limited 340.00 24.00 340.00

3min flows, 1 @ SH1 14000L, 1 @ old weir 9200L, 1 @ nth branch confluence 3400L. (Storage water in Dam crc103030)

CRC951934.2 Cairndhu Dairy Limited 341.00 5.00 71.042min flows @SH1, 1 to stop take and 1 to halve the take. (irrigation of pasture and stock water)

CRC952441 Mr & Mrs C D & L A Galloway 240.00 6.20 62.002min flows @SH1, 1 to stop take and 1 to halve the take. (irrigation of 150ha)

SCY710049 Ashburton District Council 84.00 24.00 84.00No minimum flow is required (stock and domestic water supply)

SCY710053 Ashburton District Council 1133.00 24.00 1133.00No minimum flow is required (stock and domestic water supply)

CRC002108 Ashburton District Council 20.0 10.2No min flow (domestic supply, stockwater, dairy washdown)

CRC011923 Ashburton District Council 36.0 15.3 public water supply- no minimum flow is required

Total groundwater abstractions (excluding stock water) 938.80 305.60

Stockwater (including stockwater groundwater takes) 1273.00 1242.44


Total 3398.90 2282.32

A Block 2858.90 1742.32

B block 540.00 540.00




RecordNo ClientName MaxRate Hours/day Rate/day Concurrent Minimum Flow Condition

CRC001953.1 NZSki Limited 28 24 28 No min flow

SCY710059 Ashburton District Council (Washpen Stream) 340 24 340

(community stock and domestic water supply). A divert into Washpen Stream of Pudding Hill take, therefore effectively not a take.

SCY710052 Ashburton District Council (Pudding Hill) 509 24 509No minimum flow is required (stock and domestic water supply)

Total groundwater abstractions 0 0

Stockwater 509 509

A Block direct surface takes (excluding stockwater) 28 28

Total 537 537

A Block 537 537

B block 0 0

A Block surface and groundwater takes with NO minimum flow (excluding stockwater) 28 28A Block surface and groundwater takes with minimum flow 0 0

Surface water takes in Pudding Hill


Rate/day or

RecordNo ClientName MaxRate Hours/day Stream depletion Concurrent Minimum Flow Condition

CRC000248.1 James & Clare Freeth Limited 23.0 4.4 no min flow (irrigate 50ha)

CRC000305 C G & H K Rapsey 45.0 0.0 no min flow (irrigate 160ha)

CRC020255.1 Messrs A J & M J Sim 22.0 1.7 no min flow (irrigate crops and pasture)

CRC020255.1 Messrs A J & M J Sim 22.0 0.0 no min flow (irrigate crops and pasture)

CRC020257.1 Mr & Mrs G M & S M Fechney 66.0 6.1 no min flow (irrigate crops and pasture)

CRC021572.1 Mr & Mrs G M & J M Waddell 65.0 0.6 no min flow (irrigate crops and pasture)

CRC032236.1 Delos Farm Ltd 232.0 2.5 no min flow (irrigate pasture - dairy)

CRC032236.1 Delos Farm Ltd 232.0 1.4 no min flow (irrigate pasture - dairy)

CRC040613.5 Westerfield Water Limited 199.0 3.1 no min flow (irrigate crops and pasture)

CRC042190.2 Gregory Partnership 73.4 3.2 no min flow (irrigate crops and pasture)

CRC051210.1 Pekanga O Te Awa Farms Limited 105.0 20.0 no min flow (irrigate pasture)

CRC054425 Tullymett Farm Limited 120.0 15.7 min flow@ SH1 14000L (irrigate crops and pasture)

CRC960050.2 Mr J F Snowden 38.0 16.7 min flow at SH1 (irrigate pasture)

CRC960050.2 Mr J F Snowden 38.0 16.7 min flow at SH1 (irrigate pasture)Spk to Matt

CRC982179 Delos Farm Ltd 75.0 32.02 min flows @ SH1 1 to stop take, 1 to halve take (irrigate 318ha)

CRC960050.2 Mr J F Snowdon 38.0 16.7 no min flow

CRC921547J Greenstreet Irrigation Society Limited 230 2.7 25.882min flows @SH1, 1 to stop take and 1 to halve the take (To take water from Spring Creek and irrigate

CRC921547C Greenstreet Irrigation Society Limited 990 14 577.50 min flow SH1

CRC921547H Greenstreet Irrigation Society Limited 230 5.00 47.92 min flows @ SH1, 1 to stop take and 1 to halve the take. (irrigate 114ha)

CRC951119 Gregory Partnership 23 24 23.003 min flows @SH1. 1 to stop take, 1 to halve take and 1 is an error. (spray irrigation)

CRC951552 Mr D G Aschen 240 1 10.00

2min flows @SH1, 1 to stop take and 1 to halve the take. (take from Sth Branch to augment flow in unnamed stream)

CRC951747 Mr D G Aschen 240 1 10.00

2min flows @SH1, 1 to stop take and 1 to halve the take. (take from unnamed stream and irrigate 25ha pasture)

CRC951956 Mr & Mrs R J & B J Tait 38 15.7 24.86

2min flows @SH1, 1 to stop take and 1 to halve the take.( take water from hole adjacent to Ashburton river for irrigation purposes)

CRC952061.1 Mertyn Trust 85 15.2 53.832min flows @ SH1, 1 to stop take and 1 to halve the take. (take water from sth branch to irrigate 131ha)

SCY710035 Ashburton District Council (Langdons) 42 24 42.00No min is required (divert & take from sth branch community stock and domestic water supply)

CRC980746 Ashburton District Council (Langdons) 120 24 120.00


Stockwater 162.00 162.00


Total 3631.40 1075.70

A Block 3631.40 1075.70

B block 0.00 0.00

A Block surface and groundwater takes with NO minimum flow (excluding stockwater) 1122.40 59.62A Block surface and groundwater takes with minimum flow 2347 854.07

Surface water takes in South Branch (Lower)



CRC022038 Mr & Mrs R G & N T Read 4.9 2.7 no min flow (irrigation crops and pasture)

CRC040705.3 Mr C A & Mrs E M Hill and Myers & Co Trustees Limited 4.4 0.0 no min flow (irrigate vineyard)

CRC050225.1 Ashburton District Council 630.0 0.6 (community water supply)


CRC050225.1 Ashburton District Council 630.0 0.2 (community water supply


CRC110621 Mr W J & Mrs J L Donald 38.0 15.8 2 min flows @ SH1

CRC021793 Ashburton contracting LTD 23.0 3.7 no min flow

CRC022052.15 Mr P J & Mrs G S Watson 31.0 2.5 min flow at SH1

CRC991408 Fulton Hogan 12.6 9.1 no min flowTotal groundwater abstractions (excluding community water supply) 88.40 33.80Community water supply 2520.00 5.50


Total 2633.90 39.30

A Block 2633.90 39.30

B block 0.00 0.00



Surface water takes in Asburton Mainstem (Upper above SH1)

ashburton/hakatere river flow and allocation regimes

Documents